fix/df-973: Handles invalid unicode in email fields

[jbarnsley10]

Proposed change

Shows a validation error if an email address is entered that contains invalid (unicode) characters. A specific error message is shown (rather than the generic 'wrong format') so a user can determine that for example the type of dash is incorrect.

This PR will need a model bump of defra/forms-model once the designer PR has been merged DEFRA/forms-designer#1378

Jira ticket: DF-973DF-973

Type of change

• Bug fix
• New feature
• Breaking change
• Misc. (documentation, build updates, etc)

Checklist

• You have executed this code locally and it performs as expected.
• You have added tests to verify your code works.
• You have added code comments and JSDoc, where appropriate.
• There is no commented-out code.
• You have added developer docs in README.md and docs/* (where appropriate, e.g. new features).
• The tests are passing (npm run test).
• The linting checks are passing (npm run lint).
• The code has been formatted (npm run format).